1. Field of the Invention
The present invention relates to a needle holder for medical syringes, such as injection syringes and syringes for the removal of body fluids and for, vials such as eyedrop vials, and the like.
2. Description of the Prior Art
With medical syringes, in particular injection syringes, the holder for the hollow needle or cannula is so formed that it is with difficulty that the needle and associated preparation holder can be connected together in a sturdy unit in a simple manner while avoiding the danger of infection. In many cases, the needle together with a base body to which it is connected and a protective sleeve which surrounds the free end of the needle are kept sterile in a sealed packaging. After the removel from the packaging, the base body is mounted on a sterile end of the preparation holder which is provided with a puncturable closure, whereby the end of the hollow needle from the protective sleeve punctures the closure. The preparation holder with the so engaged needle is inserted in a syringe body, which is ordinarily formed out of metal and to the entire arrangement imparts the necessary strength to the application. This mode of operation is not only complicated but also brings the danger of infection with it since the puncturable closure of the preparation holder and the therewith connected end of the needle must be exposed before their joinder and under these conditions can become contaminated. Another disadvantage is the requirement that an additional syringe body be used which is not only inconvenient but is also productive of additional danger of infection.
There are therefore known ampule syringes in which the preparation holder serves simultaneously as the syringe body. Such syringes are ordinarily suitable for a single use and the simple and inexpensive construction required for such service makes it naturally difficult to form the needle holder with sufficient strength and load capacity. A known solution suggested in this regard exists in which with ampule syringes, the needle is mounted on the preparation holer (ampule or syringe body). A sealing arrangement must naturally be provided which hinders the flow of the preparation out of the needle until immediately before the operation of the gasket arrangement is made ineffective. As the gasket arrangement employs, for example, the protective sleeve, this then on its closed end is provided interiorly with a sealing material, for example a rubber stopper which closes the outer end of the needle until removal of the protective sleeve. The permanent contact of the preparation with the metal needle produced by this ampule construction is however, most undesired. It is therefore further known for the sealing device to provide additionally a puncturable closure on the preparation holder and an arrangement so to form that by retention of the covering effected by the protective sleeve against surrounding action a relative movement between the closure and the needle can be defined through which the needle punctures the closure. The closure and/or the needle can thus be moved. It is difficult to produce a needle holder which renders such relative motion with the necessary reliability and convenient service and which needle holder is also sufficiently simple to be suitable for use with a single use syringe.